gastric motility and pancreatic function Flashcards
What is the function of the peristaltic wave
Helps move food from the stomach body to the antrum
Where in the stomach does digestion occur
Antrum due to the thick muscle
What is gastrin’s effect on the peristaltic wave
Increases contraction
Describe how food goes from the antrum to the pyloric sphincter
The food in the antrum is like clothes in the washing machine, the food will go to the pyloric sphincter which may be closed and if so will go back to the body and do the mixing cycle at the antrum again
What is the effect of fat/acid/amino acid in duodenums affect on gastric peristalsis
inhibition of motility
What is the effect of a distended stomach on gastric peristalsis
Increased contractions
What is the link between number of action potentials and peristalsis contractions
The greater the number of potentials, the stronger the contraction
How is acid in the duodenum neutralised
Bicarbonate released from the Brunner’s glands which are present in the submucosa of the duodenum
What does acid in the duodenum trigger
Long (vagal) and short (ENS) reflexes - stimulate bicarbonate secretion
Release of secretin from S cells which causes increased bicarbonate secretion from pancreas and liver
What is the function of an endocrine hormone
Secretes hormone into the blood directly
What is the function of exocrine glands
Secrete hormones through ducts
What is the function of the sphincter of Oddi
Controls secretion of bile and pancreatic juice to the duodenum through the ampulla of vater
What is the function of the pancreas
Secretion of bicarbonate by duct cells
Secretion of digestive enzymes by acinar cells
What 2 ducts connect at the ampulla of vater
Common bile duct and pancreatic duct
How do the digestive enzymes in the pancreas work
They are zymogens to prevent the pancreas getting digested so they get activated once they leave
Enterokinase which is bound to the brush border of the duodenum converts trypsinogen to trypsin which activates all the other zymogens
